Coating for fibrous glass strands



Feb. 10, 1942. A. L. SIMISON 2,272,588

COATING FOR FIBROUS GLASS STRANDS Filed July 31, 1937 24 w in 4M'M-W 50 INVENTOR. a 2 K BY 5i ATTORNEYS.

1 conventional textile machines.

Patented Feb. 10, 1942 UNITED STATES PATENT OFFICE coA'rmG roa rmnous crass STRANDS Allen L. Simison, Newark, Ohio, assignor, by mesne assignments, to Owens-Corning Fiberglas Corporation, a corporation of Delaware Application July 31, 1937, Serial No. 156,627-

3 Claims.

' duction of a plurality of extremely fine, long,

continuous fibers, as, for example, by the method illustrated and described in the copending appli-' cation of Slayter and Thomas, Serial Number 105,405, filed October 13, 1936, now Patent No. 2,234,986 dated March 18, 1941, it has been found that the speed of attenuation and production of fibers was limited by the speeds at which the fibers could be formed into strands and wound on packages in such a manner that the strands could be unwound and processed thereafter in the It is anobject of the invention to permit glass fibers to be produced at extremely high speeds, as, for example, above 5,000 or even 20,000 feet per minute, and yet enable the fibers to be gathered into strand form and packaged into a useful article.

One of the primary objects of the coating itself is to bond the fibers together in strand form prior to twisting without fraying or subdividing. Once extremely fine fibers, that is, below .0004 inch and particularly below about .0002 inch in diameter, have been intertwisted into a twisted thread, they will retain their coherence and strength without fraying or subdividing and without the necessity of an adhesive or coating material. Before twisting and when in strand form without proper adhesive, it is difficult to handle the strands and process them through the conventional textile machines.

Anotherobject of the coating material is to retain the loose ends of any broken fibers in the strand without permitting them to break away and form a-fuzz.

from a wound package thereof, owing to the fact that a loose fiber continues to break away from the main body of the strand as it is unwound and produces a fuzz around the package as the loose fiber is broken by the subsequent unwindings of the main body of the strand. This causes other fibers to be broken away from the strand until the package is destroyed.

Another object of the invention is to provide a coating substance which will readily distribute itself uniformly over the fibers at extremely high speeds.

This feature is particularly important whenattempting to unwind a strand In order to apply a coating at the high speeds mentioned hereinabove, the substance must be sufiiciently fluid at the time of application so that it may be distributed uniformly and thinly over the fibers as it is being applied.

In this connection another important object of the invention is to provide a coating material which will be solidified and free from tackiness before it reaches the package. At extremely high speeds of about 5,000 to 10,000 feet per minute, the coating would have to substantially solidify in about [5 to ,5 of a second after application.

If the coating is not sufiiciently solid by the time it reaches the package, the coating of one strand will tend to conflow with the coatings of adjacent strands on the package and thus bond the windings of the strand on the package to a unitary mass which cannot be unwound. It has been found that coatings requiring the volatilization of a solvent generally require an excessive amount of time to solidify. 1

Another important object of the invention is to provide a coating which is readily removable from the strand at any stage of the fabrication, that is, after twisting, weaving, braiding, knitting, or the like. After the fibers have been fabricated into the finished product, it is generally desired to remove all or substantially all of the organic substances therefrom in order to produce a pure, wholly inorganic material which is fireproof, rotproof, waterproof, etc. Coating substances requiring expensive solvents or a lengthy process of. removal, are not desirable owing to the increased cost of fabrication and processing of the material. e

Other objects and advantages of the present invention will become apparent from the following description taken in conjunction with the drawing, in which:

Fig. l is a diagrammatic elevational view shown partly insection of an apparatus for attenuating a multiplicity of fine glass fibers of substantially continuous length, groupingthem in strand form, and applying a coating thereto in accordance with the present invention;

Fig. 2 is a diagrammatic elevational end view showing partly in section the apparatus depicted in Fig. 1; and

Fig. 3 is a detailed section view of a waxer.

In order to carry out the foregoing objects, I have discovered that thermoplastic substances,

as for example, esters of high atomic alcohols,

such aswaxes, serve admirably as coatings for strands composed of fine glass filaments and enable the production thereof to be carried on at speeds far higher than those used heretofore.

Various waxes may be used as, for example, cerese wax, mineral waxes, paraflin wax, carnauba wax, Japan wax, vegetable waxes, beeswax, or the like or mixtures thereof. The waxes are applied in a molten condition, generally in the neighborhood of about 120 F. to 190 F. In melted form, the waxes may be applied by any suitable means such as a pad, groove, roller, or other suitable methods. The glass strands are passed through the molten wax, or films thereof, picking up the proper amount, and then are passed through a cooler zone which freezes the wax almost instantaneously and produces a firm, flexible, coherent strand which may easily be wound upon a package. In winding the strands over a package, it is preferable to traverse the strand as it is being wound in order to wind the strand uniformly and evenly and in a manner which facilitates easy unwinding.

While, as brought out hereinabove, various waxes may be used, it is preferable to use a wax which is slightly plastic at room temperature although not too soft and tacky. If the wax is too stiff and brittle at room temperature, or temperatures at which the package is used, the wax tends to convert the strand into a solid, stiff rod which is frangible and easily breaks on bending or slight twisting. On the other hand, if the wax is too soft, it will tend to be too tacky or sticky on the package and during fabrication, and thus will prevent easy and smooth unwinding of the strand from the spool, and, during manipulation of the strand, the wax thereon will tend to accumulate on eyes or other objects with which the strand comes in contact.

In this connection, it has been found preferable to provide waxes having melting temperatures in the range of about 150 F. to 170 F., although variations from this range are permissible owing to the fact that the important properties of plasticity, softness and freedom from tackiness, should be at room temperature.

The wax is generally applied in amounts, which, in comparison with the weight of the filaments are within a range of about to 30 per cent, although preferably in the neighborhood of about to per cent depending on the fiber diameter and the number of fibers in the strand. In standard practice about 18 per cent is gen-' erally applied. If too little wax is used, the fibers in the strand are not held sumciently firmly together, and vibration or other action of the .machine may tend to separate the strands into If, on the other hand,

two or more smaller ones. too much wax is applied, there will be a tendency toward the formation of beads along the strand, which are undesirable and prevent manipulation and proper handling of the strand.

Referring now more particularly to the drawing, reference character l0 designates a refractory furnace having an inner lining in the form of a V-shaped trough ll, preferably made of a high melting point metal such as platinum or platinum alloy, containing a body of molten glass. A series of outlet openings l2, having diameters of about .025 to .08 inch, are provided at the lower portion thereof at the convergence of the converging sides of the trough II. In order to provide as high per cent production of filaments as possible, it is desirable to provide a multiplicity of outlets 12, as, for example, about fifty to several hundred openings, according to the size and design of the trough ll Spaced below the openings i2 is a blower 13 adapted to impinge a blast of cooling gas, such as steam or compressed air, upon the filaments as they are being attenuated from the individual nipples whereby they are chilled almost immediately into the form of a fine,

solid filament.

Arranged below the furnace and floor a suitable distance is one or more grouping and waxing devices I5 adapted to draw the individual filaments together into a strand form and simultaneously apply a wax coating thereto. Ordinarily one waxer I5 is sufficient, but at extremely high speeds it has been found advantageous to use a plurality, ach providing a light coating.

After the fibers have been grouped and suitably coated with a waxing material, the wax is solidified rapidly by cooling to form a unitary strand and is then wound over a revolving winder i8. In winding the strand upon the winder 18, it is desirable to traverse the yarn by means of the traverse I9 in order to form a uniform, easily unwindable package.

As may be observed more readily in Fig. 3, the waxer I5 comprises a receptacle 20 having a hinged lid 2| into which wax may be fed. Arranged preferably in the lower portion of the container 20 is a heating means 22 such as an immersion type heater using about 100 watts of electrical current supplied by an electrical energy source 23.

The wax is fed from the container 20 through an orifice 24 which is provided with an adjustable needle 25 having an adjusting means 26 similar in design to a conventional oil dripper. Spaced below the orifice 24 is a platen 21 which may be covered along the upper portion thereof with a pad 28 upon which the molten wax drips, maintaining the pad in a saturated condition. The platen 21 is held in an adjustable position by means of a bracket arm 29 extending from the receptacle 20. A suitable heating means 30 electrically connected to a current source 30- may be mounted in the platen 21 serving to maintain the wax at the proper temperature as it is being applied.

The platen 2'! is also provided with a peripheral groove 3| serving to group the fibers into strand form. The groove 3| may be more readily seen in Fig. 2.

The glass filaments or fibers emerging from the bushing orifices H, are individually drawn over the saturated felt pad 28 and are coated with a thin film of molten wax, and are then grouped together and compacted in strand form by means of the groove 3|. The excess wax which drips from the platen 21 may be recovered in a suitable receptacle 32 (see Fig. 1).

If desired, a plurality of waxers I5 may be provided as shown in Fig. 1. This is desirable when applying wax at extremely high speeds since it has been found that by this arrangement the wax may be more uniformly applied to both sides of the strand after the strand is a whole. When using a plurality of waxers IE, it is generally desirable to arrange them at alternate sides of the strand in order that all sides may be uniformly and equally coated with wax material.

The winder ll comprises a revolving drum 35 over which snugly fits a roll or spool, such as cylindrical cardboard tube 38. The drum may aaraees been found satisfactory. In order to conserve space, it is possible to provide a chilling or cooling means 40 for the strand such as a blower adapted to direct a blast ofcooling air along the strand as it is being drawn away from the waxer.

Ordinarily, however, such cooling means is unnecessary owing to the characteristic property of rapid solidification possessed by the wax causing the fibers to quickly form a compact coherent strand. It is also desirable to reduce the amount of friction between the orifices l2 and the winder 88 as much as possible in order to prevent undue compacting of the strand upon the package. In order to reduce this friction at high speeds, it has been found advantageous to avoid drawing the fibers or the strand around sharp corners or wide angle turns.

After the spool 36 has been filled and covered with a package composed of glass strand, it may be removed and the strand thereon processed through the subsequent desired textile machines such as twisters, winders, or looms. During these subsequent operations,- the wax serves to hold the individual fibers or filaments within the strand, in spite of the fact that they are laid in parallel relationship and have no twisting, and in spite of the fact that various ends or indivldual filamentsmay have been. broken, for example, during the attenuation and forming process;

interjacent the fibers, serves to minimize this efiect and lubricates the fibers from one another whereby they mayslip past one another without fracturing or scratching each other.

Modifications and variations may be resorted to within the scope and spirit of the present invention as defined in the appended claims.

I claim:

1. The method of producing a glass'textile strand which comprises simultaneously and continuously drawing a multiplicity of fine glass filaments from a supply body of molten glass at a speed of at least 5,000 feet per minute, continuouslywinding the said filaments in strand form into a package, simultaneously and con-- tinuously grouping the filaments at a point between said supply and package into the form of a strand with the filaments substantially par- After the strands have been fabricated into the finished product, as, for example, in a woven, knitted, braided, or otherwise interlaced glass fabric, it is desired to remove the wax. This may easily be done by a rapid washing of the fabric in a soap solution. The soap readily emulsifles the wax and causes it to rise as a scum to the surface of the wash solution.

In order to quicken even further the removal process, it is possible to apply various emulsifying agents to the wax such as triethanolamine, bentonite, soaps, etc.- Triethanolamine is preferable owing to the fact that only a small amount of it is necessary for emulsifying purposes.

It is also to be observed that the wax also performs the function of lubricating the individual filaments during the fabrication process. As

the strand is twisted into threads, yarns, or

coating of wax, not only over the strand but also allel in the strand, and at said point coating the filaments with molten wax capable of solidifying solely by cooling within a small fraction of a second prior to said filaments reaching said package. Y

2. The method of producing a glass textile strand which comprises simultaneously and continuously drawing a multiplicity of fine glass filaments from a supply body of molten glass at a speed of at least 5,000 feet per minute, continuously winding the said filaments in strand form into a package, simultaneously and continuously grouping the filaments at a point between said supply and package in the form of a strand with the filaments substantially parallel in the strand, and at said point coating the filaments with molten wax, in the ratio of 10% to 30% by weight, of wax to filaments, which is slightly plastic though not tacky. at room temperature and has a melting temperature in the range of F. to F. and is capable-of solidifying solely by cooling within a small fraction of a second prior to said filaments reaching.

said package.

3. The method of producing a glass textile strand which comprises simultaneously and continuously drawing a multiplicity of fine glass filaments from a supply body of molten glass at a speed of at least 5,000 feet per minute, continuously winding the said filaments in strand form into a package, simultaneously and continuously grouping the filaments at a point between said supply and package in the form of a strand with the filaments substantially parallel in the strand, at said point coating-the filaments with molten wax, in the ratio of 10% to 30% by weight, of wax to filaments, which is slightly plastic though not tacky at room temperature and has a melting temperature in the range of 150 F. to 170 F. and is capable of solidifying solely by cooling within a small fraction of a second prior to said filaments reaching said package, and cooling the wax coating to solidity prior to winding on said package.

ALLEN L. SIMISO N. 

